Addresses discussions such as https://github.com/ppy/osu/discussions/26407
or https://github.com/ppy/osu/discussions/25914 wherein:
- the game would attempt to convert scores for custom rulesets, which
makes no sense, especially so when they're not there,
- the game would also "recalculate" lazer scores, but that was never the
intention or was never supported; the game would just increment the
score version on those but still include them in the converted tally.
This was a source of confusion for users previously, wondering why their
non-legacy (non-stable) scores weren't being converted in line with new
scoring changes, when it was never actually our intention to support
anything of the sort.